This Phase I SBIR project will demonstrate an innovative cancer screening and diagnostic test based on the molecular tumor marker cancer specific proliferating cell nuclear antigen (csPCNA). A new compact device, the csPCNA Immunosensor, will be designed and constructed based on input from initial data. The proposed csPCNA Immunosensor has the potential to save lives and significantly reduce health care costs through more effective and earlier detection of the disease. The test can be performed in the physician?s office or clinic. The project will incorporate three innovative technologies: * A recently identified monoclonal antibody for the tumor marker csPSNA, * A sensitive and rapid integrating waveguide biosensor, and * A novel assay surface preparation method utilizing nanomanipulation. Many cancer markers are available commercially but most lack sensitivity and selectivity. Currently available gene tests can indicate cancer risk but may not reliably confirm the presence of the disease. By contrast, csPCNA has been shown present in 100% of the 60 cancer cells tested, but has not been found in normal cells or benign tumors. The csPCNA Immunosensor can simplify cancer screening and reduce cost because a single test can detect a whole range of cancers. The csPCNA Immunosensor can also provide prognostic information for tracking treatment progress and follow-up monitoring of patients in remission. The test will be far less expensive than magnetic resonance imaging (MRI),x-raycomputed tomography (CT), or PET. PROPOSED COMMERCIAL APPLICATION: This test can be used for cancer screening and diagnosis, which are $8 billion and $4.5 billion annual markets in the U.S. alone. Currently some 50 million Pap smears, 30 million mammograms, 30 million PSA tests, 20 million occult blood tests, and 2.5 million biopsies are performed annually for these purposes.